According to a related audio coding and decoding technology, a plurality of audio objects composed with various channels cannot be mixed according to user's needs. Therefore, audio contents cannot be consumed in various forms. That is, the related audio coding, and decoding technology only enables a user to passively consume audio contents.
As a related technology, a spatial audio coding (SAC) technology encodes a multi channel audio signal to a down mixed mono channel or a down mixed stereo channel signal with spatial cue information and transmits high quality multi channel signal even at a low bit rate. The SAC technology analyzes an audio signal by a sub-band and restores an original multi channel audio signal from the down mixed mono channel or the down mixed stereo channel signals based on the spatial cue information corresponding to each of the sub-bands. The spatial cue information includes information for restoring an original signal in a decoding operation and decides an audio quality of an audio signal reproduced in a SAC decoding apparatus. Moving Picture Experts Group (MPEG) has been progressing standardization of the SAC technology as MPEG Surround (MPS) and uses channel level difference (CLD) as spatial cue.
Since the SAC technology allows a user to encode and decode only one audio object of a multi channel audio signal, a user cannot encode and decode a multi object audio signal with multi channel using the SAC technology. That is, various objects of an audio signal composed with a mono channel, a stereo channel, and a 5.1 channel cannot be encoded or decoded according to the SAC technology.
As another related technology, a binaural cue coding (BCC) technology enables a user to encode and decode only a multi object audio signal with a mono channel. Thus, a user cannot encode or decode multi object audio signals with multiple channels, except the multi object audio signal with the mono channel, using the BCC technology.
As described above, the related technologies only allow a user to encode and decode a multi object audio signal with a mono channel or a single object audio signal with multi channel. That is, a multi object audio signal with multi channel cannot be encoded and decoded according to the related technologies. Therefore, a plurality of audio objects composed with various channels cannot be mixed in various ways according to a user's needs, and audio contents cannot be consumed in various forms. That is, the related technologies only enable a user to passively consume audio contents.
Therefore, there has been a demand for an apparatus and method for encoding and decoding a multi object audio signal with multi channel in order to enable a user to consume one audio contents in various forms by controlling the multi object audio signal according to user's needs.